Intercommunicating telephone system.



R. H. MANSON. INTERGOMMUNIGATING TELEPHONE SYSTEM.

APPLICATION FILED MAY 29, 1907.

Patented Feb. 21, 1911.

3 SHEETS-SHEET 1.

Euuauloz I WE h: 200::

R. H. Lawson.

INTERCOMMUNMATING TELEPHONE SYSTEHL APPLICATION F1123] MAY 29, 1907.

Wil'ncmu Patented Feb. 21, 1911.

V 3 SHBETSSHEET 2.

SHEETS-SHEET 3.

R; H. MANSON. INTERCOMMUNIGATING TELEPHONE SYSTEM APPLIGATION FILED muss. 1907. 984,686, Patented Feb. 21, 1911.

ave-"1oz allow 3/ 96 huzaoeo v UNI ED STATES PATENT. oFEioE.

RAY H. MANSON, OF ELYRIA, OHIO, ASSIGNOR TO THE DEAN ELECTRIC o'oMrA'nY. on

ELYRIA, OHIO. A CORPORATION OF 01110.

,INTEBCOMMUNICATING TELEPHONE SYSTEM.

Application filed May 29, i907. Serial No. 376.420.

'To all whom it may. concern:

Be it known that I, RAY H. Maxsox, a citizen of the United States, residing at Elyria, in the county of Lorain and State-of ()hio, have invented certain new and useful Improvements in lntercomnmnieating Telephone Systems, of which the followin is a specification, reference being had therein to the accompanying drawing:

My invention relates to interconnnunicat ing telephone systems, and consists in the arrangements and coi-nhinations hereinafter described and claimed.

An object of my invention is to provide a telephonesystem of the class named. with indicating keys for switching the stations. to take the place ofthe ordinary forms of con- I necting cords with their necessary plugs and jacks, or. where these parts are not used, to obviate the objections arising outof the use of the ordinary switches for putting into communication he various parties on the line.

ll'ith this and other ends in view, I have devised a common battery system, and have provn ed therefor a series or indicating keys which serve the purpose of connecting the various parties on the line, of operating their :ignal hells. of cutting'ofl the. ringing current, and finally of switching on the talking current. These keys are arranged in sets and are so constructed that when one lishes talking communication and also indicates the station that is connected. while the third position is the normal position of disconnection.

A further object of my invention is to so arrange an interconnnunicating telephone set that by the addition of an extra key and signaling devices one. of the stations on the line may serve as an attendant station in private branch exchange work, the extra key sorting to hold the main trunk while the attendant calls the subscriber wanted.

further object of my invention is to provide the extra trunk holding keys at the attendant stationwhen the system is designml for private branch exchange work, with aa- Specification of Letters Patent.

toniatic. means for breaking the through the contacts of the extra key Lis atent etl Feb. 21 .191 f 1.

c. o as the called party responds and takes npitli e; trunk, in case the attendant should neglect to release the trunk holding key. f w I My invention provides a system in wliiclif the hook switch is so wired that the lrey-' (:ii"- coils of a particular station are out off when: that station is not in use, thus rendering it unnecessary to restore the keys whenthrough talking.

Other objects and advantages of my in-j; vcnti'on will he more clearly set forth'in the specific description of the system asset forth in the body of the specification. 7

My invention is illustrated in the acconh panying drawings in which- Figure 1 15 a side elevation showing a set; of swltch keys. 1* 1g. 2 1s an end view, partly'f m section. showing the construction of a key. Fig. 3 an end view showing the mas ter ringin z contact. 'Fig. 4: is a diagrammatie view showing the general arrangem nt of my improved imet-communicating' system. Fig. 5 is a diagrammatic view showing the arrangement at the attendants station of an automatic disconnect mechanism for the trunk holding key.

Referring to the drawings, 1 designates'zi I rectangular frame provided with push buttons disposed on the ends of the rods 3' and adapted to rcci n'ocate in openings 4 in the frame 1. Spiral springs 5 arrangedon' rednced portionsof the rods 3 serve to keep said rods in a normally raised position. 9Q .lonrnaled in slots 6 in the rods 3 are the' cam rollers 7 of insulating material, while projecting laterally from said rods are the pins 8 and S. Pivoted on the frame 1 at 9" and 9 are the inturned ends 10 and 10 of 5- the locking plate 11 which is provided with openings 12 for the purpose of receiving the pins 8 and 8' to lock the keys 2. in a manner;- hereinafter described. At, one-end ofthe'a frame 1 there is located a master contact. 0

which is designed to he closed on the .depr'es-.-

sion of any one of the keys to its lowest posi; 1. tion and which is opened again on the release of the keys. Reference to Figs. land 3- will show that theplate 11 has a hook-like extension 1'3 adapted to hear on an insulat ing hearin; memhcr 14 carried by a contact, spring 15. the latter being, provided wilh;a contact point 1. It will be seen that ont lre repression or any one he; the pin 8 will n w. w

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the key in position.

I depressed the locking plate 11 is formed backward by means of the pins 8 and 8' and longer than the lower come in contact with the cam surface 12' on the locking plate lfl'while on furtherdepres- 'sion of the. key the upper pin 8 which is p in will engage the cam surface 12 and ti t the locking plate backward from the frame. The upper pin, however, never gets below the cam surface on account of the button 2 engaging the upper surface of the frame. The movement of 'the rod 3 is sufficient, however, when the key "has been depressed to its lowest position and the pin 8' has ergaged the cam surface 12, to actuate the locking plate as above explained to cause the hook-like extension 13 to bear againstthe spring 15 and to force its contact 16 against the anvil 17 This con tact will be kept closed as long as any one of the keys is depressed to its limit, but owing to the action of the spring 15 the locking plate will be returned to its original position when pressure on the button is relieved.

f The key however will not return to its original position but. will assume an intermediate position due to thefact that the pin 8 engages the edge of the opening 12 which locks W'hen another key is the first key which had been locked in its intermediate position is now released and assumes its normal osition. It-will be rcadi v seen from the above description that on depression of any one or" the keys to its lowest position the master contact will be closed and any other key will be released. As clearly shown in Fig. l the cam rollers 7 on coming into contactwith the springs 18 will force the latter against their anvils 19 and thus complete circuits through these parts. It will be noted that in the intermedia e position of the key, the

. latter contacts are closed.

I have described above a set of keys that is peculiarly adapted for use in an intercommunicating telephone system. It will he ,nnderstood that other specific forms ofkeys {could be used without departing from thespirit and scope of my invention and I therefore do not wish to limit myself to the spc- 'cific construction herein described.

The arrangement of my improved circuits: is well illustrated in Fig. 4. in which the ringing battery is shown -at R. and the talking battery at '1. Connecting the various R normally supported on the sw:

' the master ringing contact (1,. Current now The conductors lines t and i are used for the ta king circuit in private branch exchange work." These keys are designated on the drawings a K l\'.. K The master ringing contact of each set is shown at C C, The connections between the various parts are plainly shown in the drawing and these parts include the ordinary receivers R R. :h hooks 5,. S and connected in the bridge wire of a li heatstone bridge having choke coils intwo of its arms and balancing non-induciive resistances in the other two. the above arrangement a ingfor the purpo e of preventing the battery currents from atl'ecting the rcceiv r whilepermitting the voice cirrents to pass through it. T T T are the transmitters and B B B are the signal bells.

The operation of my invention as follows: ll'hen a party at any one of the stations desires counuuuicati n with another station. f r instance. it the part at station 1 wishes coninuu'iication with station 3. he presses the key to its lowest limit. closi flows from the ringing barte v following path: R. r. (5;, C

2' B S .land r. '1. 'ie pal station 3 responds by pressing his home but ten. 2'. 6., the button numbered the ..@e as the station at which it is located. lie then takes his receive]: off the hook switch. thereby completing the talking circuit at his end or? the line through the contact on the upper side of the hook switch 5 while the party at station 1 does the same at his end of the line. Both teicpl'lones are n w l ridged acz the l'tPS-Llt("t.iil from the coalition battery T. The followingcircuit is complete-1t through the telephone at station 3: T, :c c. I.,, min, :5 T:- a: zn pas fa: ya: e: and The circuit through the telephone at station 1 is completed as follows: T. (c c. 3 727- in. r T1: R17 P11 1.1 fl: 1 /1: g1: 01 AS has been before stated, when the pressure on a key is released it returns only part way, thus serving as an indication ot'ihe station connected. This slight movement of the button i sufiicient however to open up the master ringing contact and leave the system ready for talking. It will be seen that it is 'not necessary to restore these keys when battery. The depressed keys however are locked in their retracted or intermediate positions and the circuits controlled through these keys,'in this positioii, are maintained closed as long as desired. As soon as the receivers have been again hung up the line is restored. to its normal condition.

-This. interconnnunicating telephone system is .particularly adapted for private branch-exchange work, as a trunk circuitto the main exchange can be multiplied through a.l the'intercommunicating telephones and can terminate on buttons the same as the regular stations. When the systern is thus arranged it is desirable'to have one of the telephones serve as an attendant or operator station, an extension bell E being bridged across the trunk circuit in series party desired "is known, the trunk can bc held by means of a special key V provided with a retardation coil V; while the attendantoperator calls up the desired station by' means of the proper button. As soon as the party respom s and takes up the trunk the attendant releases the holding key, and constation 1 should neglect to'release the holding key V it. would ofcourse-prevent the releasing of linesignals at the main exchange after the parties are through talkin". To provide against such a contingency I have devised a means for automatically disconnecting the trunk coil from the circuit when the;r'ece ivcr at the attendant station is placed on -its hook. T his device is clearly shown in Fig; In this figure there 15 shown an extra contact 3 above the hook switch and adapted to be closed by the latter when the receiver is removed from the hook. T he operators trunk holding key is adapted in this instanceto close a contact on one side only, viz. the contact at 6 It will be noted that after the receiver is removed and the trunk holding key. which in this case is made nonlocking, is depressed. the circuit from the ringing battervis closed through the following path: R. 1'. (l locking relay H, il 15,. 1' 1' 1- and back to battery. The relay II pulls up it's armatures at' both ends and the circuit through the winding of said relay is now looked through the contact w conductor 2,. and contact 8,. The contact- 1 is now closed and the circuit through the retardation coil \V is completed. When the attendant hangs up her receiver the locking circuit is broken at the Contact 8,, the magnetof the relay H iets go and the circuit through the retardation coil is broken, thus permitting the trunk line signalsat the main exchange to be released when 'the'talking partv hangs up.

diflerent stations may be connectedthrough comparatively simple means. The operation of the spring controlled push keys in the automatic releasing of adjacent keys, in

the closing of the master ringing contact and inthe openingaif thelatter when the pressure is relieveda;.wliile'maintaining the taiking circuits closed in the locked intero :10 It will be seen from the above description that I haxe provideda system in whichthe mediate position, is particularly 'advan-i tageons in an interconnnnilicaring system where the parties at each station necessarily have to assume part of the duties of an operator in getting the desired connections,

The pressing and releasing of the keys is an operation mnclrmore simple than the "1 1c 'of the ordinary switches o: of the cord and the necessary jacks. i

'I am aware that changes in detail may be made in both the apparatus and the circuits of my system without departing from the spirit of the invention. All such changes are within the scope of myclaims.

Having thus described my invention what I claim and'desire to sccurelby LettersPatcut is- Y a p 1. In an intercommunicating telephone system. the combination of a plurality of stations, conductors extending between. such stations. means for signaling each station by each of the other stations. means for establishing a talking condition between any two of such stations, a common battery trunk line extending from an exchange to such stations, signaling means atone of such sta tions adapted to be operated from" the exchange. a key at such last named station for connecting such station to the trunk line, a

self restoring key atsuch station for closing an electrical path between the conductors of the trunk line. and means for maintaining a 2. In an intercommunicating telephone system, a main exchange. trunk lines connecting said main exchange with a plurality of groups of local substationsconnected by local lines and having a con'nnon ringing circuit, GQClI-SUbSifit1OI1 having a sct'of push keys controlling said trunk'an'd 'ljocal' hues and one of said stations of each group QOI'V mg as'an attcndants station and being provided with a signal bell adapted to be rung fromthe main exchange, means 'fnr ringing 4 up any one station of a group, on the manipself-restoring 'push key bridged across the y l I ulation of a key at the attendant's station. a f

i l I g.

ringing circuitand having in series therewith a locking relay adapted to control a trunk holding circuit, means for breaking the circuit through said locking relay when the attendant hangs up her receiver. thus disconnecting the trunk holding circuit, and

means for establishing talking communication between any two substations of different groups in the system by the manipula- \ion of the trunk key at said stations.

3. In an intercommunicating telephone system, a main exchange, trunk lines connecting said main exchange with a plurality of groups of local substations connected by local lines and having acommo'n ringing circuit, each substation having a setof push keys controlling said trunk and local lines and one of said stations of each group serving as an attendants station and being provided with a signal bell adapted to be rung from the mainexchangc, means for ringing up any one station, of a group on the manipulation of a key at-the attendants station, a self restoring push key bridged across the 2-5 ringing circuitand having in series therewith a locking relay, a trunk holding circuit controlled by the armature on said locking relay and comprising a retardation coil,

means actuated when the attendant restores her hook switch to normal condition, for

- breaking the locking relay circuit, said trunk holding circuit being interrupted when said locking relay circuit is broken, and means for establishing talking communication between any'two substations of dif:

ferent groups in the system by the manipulation of the trunk key at said stations.

4. In an intercommunicating telephone system, a main exchange, trunk lines con- 40 necting said main exchange with a plurality of groups of local substations connected by local lin5s, each s ibstation having a set of push keys control. .g said trunk and local lines and one of said stations of each group serving as an attendants station and being provided with a signal bell adapted to be rung from the main exchange. means for ringing up any one station of the group on theinanipulation ot' a key at the attendants station. a ,self restoring push key at the atteudants station: for closing the trunk circuitand thus holding the trunk line untilthe called station responds, automatic means operating to disconnect the trunk holding .55 circuit when the attendant hangs up her recciver, and means for establishing talking communication between any two substations of different groups in the. system-by the manipulation of the trunk kev at said stations. 5. In an intercommumcating telephone system, a main exchange, trunk lines connecting said main exchange with a plurality of groups of local substations connected by local lines and having a common ringing'circuit, each substation having .a set. of push keys controlling said trunk and local lines and one of said stations of each group serving as an attendants station and being pro vided with a signal bell adapted to be rung from the main exchange, meansfor ringing up any one station of a group on tho; manipulation of a key at the attendants station, a trunk controlling circuit comprising a self restoring push key and a locking relay, said key and relay being bridged across the ring ing'circuit, and the armature of said relay adapted to close and open a trunk holding circuit provided with a retardation coil, and a contact at the attendants hook switch adapted to be opened when the attendant hangs up her receiver, thus breaking the cir cnit through thelocking relay and disconnecting the trunk holding circuit.

6. In an intercommnuicating -telephone system, a plurality of stations, conductors extending between such stations, means at each station for signaling a desired one of the remaining statious, means for establishing a talking condition between such two stations, a common battery trunk line extending from an exchange to such stations, signaling means at one of such stations adapted to be operated from the exchange, a key at such station for closing an electrical path between the conductors of the trunk line, means for maintaining the. closure of such path after the release of the key during the calling and connecting of another of such stations to the. trunk line, the return of the receiver to the receiver hook at such first L00 station serving to interrupt such electrical path. 7. In an intercommnnicating telephone system, a plurality of stations, conductors extending between such stations, means at each station for signaling a desired one of the remaining stations, means for establishing a talking condition between such two stations, :1 common battery trunk line extending from an exchange to such stations, signaling D]-3 H1S Zll3 one of such stations adapted to be operated from. an exchang a relay at such station adapted to close an electrical path bet-ween the conductors of the trunk line and to close a lockingcircuit through its energizing winding when operated, and a key at such station ada ted to operate such relay, the closure of such electrical path serving to hold the trunk connection during the calling and connecting of another of such stations to the trunk line, the return of the; receiver to the receiver hook atsuch' first station serving to interruptsuch locking circuit.

In testimony whereof I afiix my signature in presence of twowitnases.

RAY H. MANSON. Witnesses S. J. Romans, \V. C. S'rnoxo. 

